gnrc_slip: set NETOPT_IS_WIRED
gnrc_slip: set NETOPT_IS_WIRED

Fixes #4168

A-Paul/RIOT,rousselk/RIOT,kb2ma/RIOT,plushvoxel/RIOT,mziegert/RIOT,adrianghc/RIOT,kaspar030/RIOT,rakendrathapa/RIOT,brettswann/RIOT,dhruvvyas90/RIOT,toonst/RIOT,kerneltask/RIOT,kb2ma/RIOT,miri64/RIOT,rousselk/RIOT,miri64/RIOT,malosek/RIOT,jremmert-phytec-iot/RIOT,kerneltask/RIOT,backenklee/RIOT,RBartz/RIOT,mziegert/RIOT,wentaoshang/RIOT,herrfz/RIOT,l3nko/RIOT,malosek/RIOT,TobiasFredersdorf/RIOT,syin2/RIOT,dailab/RIOT,mfrey/RIOT,MohmadAyman/RIOT,OTAkeys/RIOT,biboc/RIOT,adjih/RIOT,beurdouche/RIOT,mtausig/RIOT,msolters/RIOT,neiljay/RIOT,Ell-i/RIOT,LudwigOrtmann/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,basilfx/RIOT,tfar/RIOT,toonst/RIOT,TobiasFredersdorf/RIOT,attdona/RIOT,jasonatran/RIOT,shady33/RIOT,kaleb-himes/RIOT,mtausig/RIOT,basilfx/RIOT,jbeyerstedt/RIOT-OTA-update,foss-for-synopsys-dwc-arc-processors/RIOT,kbumsik/RIOT,backenklee/RIOT,wentaoshang/RIOT,basilfx/RIOT,binarylemon/RIOT,kaleb-himes/RIOT,rajma996/RIOT,dailab/RIOT,biboc/RIOT,biboc/RIOT,miri64/RIOT,stevenj/RIOT,authmillenon/RIOT,Yonezawa-T2/RIOT,gebart/RIOT,A-Paul/RIOT,rfuentess/RIOT,kaleb-himes/RIOT,attdona/RIOT,Yonezawa-T2/RIOT,A-Paul/RIOT,beurdouche/RIOT,shady33/RIOT,l3nko/RIOT,altairpearl/RIOT,ant9000/RIOT,aeneby/RIOT,BytesGalore/RIOT,l3nko/RIOT,RubikonAlpha/RIOT,Yonezawa-T2/RIOT,katezilla/RIOT,roberthartung/RIOT,katezilla/RIOT,smlng/RIOT,cladmi/RIOT,zhuoshuguo/RIOT,dailab/RIOT,authmillenon/RIOT,ks156/RIOT,immesys/RiSyn,khhhh/RIOT,authmillenon/RIOT,adrianghc/RIOT,neumodisch/RIOT,stevenj/RIOT,OTAkeys/RIOT,adjih/RIOT,FrancescoErmini/RIOT,Yonezawa-T2/RIOT,roberthartung/RIOT,binarylemon/RIOT,kbumsik/RIOT,MohmadAyman/RIOT,rakendrathapa/RIOT,jbeyerstedt/RIOT-OTA-update,Ell-i/RIOT,altairpearl/RIOT,thomaseichinger/RIOT,jasonatran/RIOT,msolters/RIOT,OTAkeys/RIOT,malosek/RIOT,lazytech-org/RIOT,toonst/RIOT,dailab/RIOT,OlegHahm/RIOT,ant9000/RIOT,syin2/RIOT,rakendrathapa/RIOT,immesys/RiSyn,ks156/RIOT,stevenj/RIOT,mfrey/RIOT,kaspar030/RIOT,gautric/RIOT,RubikonAlpha/RIOT,neumodisch/RIOT,aeneby/RIOT,gebart/RIOT,khhhh/RIOT,d00616/RIOT,x3ro/RIOT,immesys/RiSyn,foss-for-synopsys-dwc-arc-processors/RIOT,shady33/RIOT,lebrush/RIOT,herrfz/RIOT,RIOT-OS/RIOT,miri64/RIOT,Josar/RIOT,gautric/RIOT,Hyungsin/RIOT-OS,jfischer-phytec-iot/RIOT,plushvoxel/RIOT,d00616/RIOT,aeneby/RIOT,adjih/RIOT,alignan/RIOT,Ell-i/RIOT,BytesGalore/RIOT,ks156/RIOT,dhruvvyas90/RIOT,rajma996/RIOT,basilfx/RIOT,neumodisch/RIOT,RBartz/RIOT,rfuentess/RIOT,TobiasFredersdorf/RIOT,attdona/RIOT,jfischer-phytec-iot/RIOT,kYc0o/RIOT,asanka-code/RIOT,adrianghc/RIOT,roberthartung/RIOT,kYc0o/RIOT,toonst/RIOT,mtausig/RIOT,basilfx/RIOT,tfar/RIOT,x3ro/RIOT,lebrush/RIOT,kaleb-himes/RIOT,jfischer-phytec-iot/RIOT,avmelnikoff/RIOT,lazytech-org/RIOT,lebrush/RIOT,dhruvvyas90/RIOT,lebrush/RIOT,alignan/RIOT,mtausig/RIOT,rajma996/RIOT,d00616/RIOT,OlegHahm/RIOT,backenklee/RIOT,hamilton-mote/RIOT-OS,syin2/RIOT,kbumsik/RIOT,msolters/RIOT,mfrey/RIOT,shady33/RIOT,yogo1212/RIOT,MohmadAyman/RIOT,RBartz/RIOT,wentaoshang/RIOT,khhhh/RIOT,rajma996/RIOT,gebart/RIOT,TobiasFredersdorf/RIOT,katezilla/RIOT,thomaseichinger/RIOT,neumodisch/RIOT,rakendrathapa/RIOT,tfar/RIOT,altairpearl/RIOT,rfuentess/RIOT,LudwigKnuepfer/RIOT,l3nko/RIOT,plushvoxel/RIOT,smlng/RIOT,gautric/RIOT,zhuoshuguo/RIOT,l3nko/RIOT,jbeyerstedt/RIOT-OTA-update,jasonatran/RIOT,Yonezawa-T2/RIOT,lebrush/RIOT,roberthartung/RIOT,rfuentess/RIOT,l3nko/RIOT,asanka-code/RIOT,brettswann/RIOT,RBartz/RIOT,OlegHahm/RIOT,zhuoshuguo/RIOT,A-Paul/RIOT,kerneltask/RIOT,toonst/RIOT,FrancescoErmini/RIOT,RIOT-OS/RIOT,altairpearl/RIOT,msolters/RIOT,alignan/RIOT,brettswann/RIOT,Hyungsin/RIOT-OS,yogo1212/RIOT,immesys/RiSyn,plushvoxel/RIOT,biboc/RIOT,MohmadAyman/RIOT,kerneltask/RIOT,d00616/RIOT,jbeyerstedt/RIOT-OTA-update,immesys/RiSyn,gautric/RIOT,avmelnikoff/RIOT,josephnoir/RIOT,BytesGalore/RIOT,kYc0o/RIOT,herrfz/RIOT,altairpearl/RIOT,ant9000/RIOT,Hyungsin/RIOT-OS,kb2ma/RIOT,lazytech-org/RIOT,RubikonAlpha/RIOT,adjih/RIOT,ant9000/RIOT,dkm/RIOT,gebart/RIOT,malosek/RIOT,zhuoshuguo/RIOT,LudwigOrtmann/RIOT,tfar/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,roberthartung/RIOT,kerneltask/RIOT,hamilton-mote/RIOT-OS,adrianghc/RIOT,yogo1212/RIOT,asanka-code/RIOT,mziegert/RIOT,jremmert-phytec-iot/RIOT,FrancescoErmini/RIOT,rfuentess/RIOT,Ell-i/RIOT,jremmert-phytec-iot/RIOT,binarylemon/RIOT,Ell-i/RIOT,attdona/RIOT,dhruvvyas90/RIOT,mziegert/RIOT,asanka-code/RIOT,gautric/RIOT,syin2/RIOT,khhhh/RIOT,MohmadAyman/RIOT,khhhh/RIOT,yogo1212/RIOT,wentaoshang/RIOT,biboc/RIOT,backenklee/RIOT,brettswann/RIOT,Hyungsin/RIOT-OS,Josar/RIOT,syin2/RIOT,msolters/RIOT,asanka-code/RIOT,josephnoir/RIOT,LudwigKnuepfer/RIOT,beurdouche/RIOT,RubikonAlpha/RIOT,A-Paul/RIOT,d00616/RIOT,kYc0o/RIOT,LudwigKnuepfer/RIOT,jbeyerstedt/RIOT-OTA-update,jasonatran/RIOT,dkm/RIOT,kaspar030/RIOT,beurdouche/RIOT,RIOT-OS/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,smlng/RIOT,smlng/RIOT,FrancescoErmini/RIOT,herrfz/RIOT,shady33/RIOT,jasonatran/RIOT,smlng/RIOT,malosek/RIOT,yogo1212/RIOT,miri64/RIOT,thomaseichinger/RIOT,lazytech-org/RIOT,khhhh/RIOT,cladmi/RIOT,hamilton-mote/RIOT-OS,foss-for-synopsys-dwc-arc-processors/RIOT,neumodisch/RIOT,adjih/RIOT,rousselk/RIOT,kaspar030/RIOT,rajma996/RIOT,dkm/RIOT,rousselk/RIOT,zhuoshuguo/RIOT,rousselk/RIOT,jremmert-phytec-iot/RIOT,mtausig/RIOT,josephnoir/RIOT,FrancescoErmini/RIOT,adrianghc/RIOT,cladmi/RIOT,neiljay/RIOT,rakendrathapa/RIOT,BytesGalore/RIOT,LudwigOrtmann/RIOT,attdona/RIOT,josephnoir/RIOT,thomaseichinger/RIOT,kaleb-himes/RIOT,zhuoshuguo/RIOT,stevenj/RIOT,wentaoshang/RIOT,TobiasFredersdorf/RIOT,aeneby/RIOT,Josar/RIOT,LudwigKnuepfer/RIOT,authmillenon/RIOT,plushvoxel/RIOT,avmelnikoff/RIOT,brettswann/RIOT,rajma996/RIOT,d00616/RIOT,authmillenon/RIOT,rakendrathapa/RIOT,LudwigOrtmann/RIOT,dkm/RIOT,brettswann/RIOT,jremmert-phytec-iot/RIOT,immesys/RiSyn,asanka-code/RIOT,MohmadAyman/RIOT,neiljay/RIOT,alignan/RIOT,x3ro/RIOT,ks156/RIOT,mziegert/RIOT,neiljay/RIOT,yogo1212/RIOT,malosek/RIOT,katezilla/RIOT,OlegHahm/RIOT,msolters/RIOT,binarylemon/RIOT,Josar/RIOT,avmelnikoff/RIOT,kbumsik/RIOT,BytesGalore/RIOT,jremmert-phytec-iot/RIOT,herrfz/RIOT,neiljay/RIOT,RubikonAlpha/RIOT,OlegHahm/RIOT,kb2ma/RIOT,OTAkeys/RIOT,thomaseichinger/RIOT,josephnoir/RIOT,herrfz/RIOT,beurdouche/RIOT,stevenj/RIOT,RBartz/RIOT,neumodisch/RIOT,dkm/RIOT,RBartz/RIOT,ant9000/RIOT,ks156/RIOT,mziegert/RIOT,binarylemon/RIOT,rousselk/RIOT,jfischer-phytec-iot/RIOT,alignan/RIOT,LudwigOrtmann/RIOT,OTAkeys/RIOT,lazytech-org/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,binarylemon/RIOT,backenklee/RIOT,jfischer-phytec-iot/RIOT,mfrey/RIOT,tfar/RIOT,LudwigOrtmann/RIOT,altairpearl/RIOT,katezilla/RIOT,x3ro/RIOT,lebrush/RIOT,hamilton-mote/RIOT-OS,kb2ma/RIOT,Yonezawa-T2/RIOT,attdona/RIOT,kYc0o/RIOT,RubikonAlpha/RIOT,hamilton-mote/RIOT-OS,dailab/RIOT,gebart/RIOT,dhruvvyas90/RIOT,FrancescoErmini/RIOT,Hyungsin/RIOT-OS,avmelnikoff/RIOT,kbumsik/RIOT,LudwigKnuepfer/RIOT,cladmi/RIOT,aeneby/RIOT,shady33/RIOT,cladmi/RIOT,mfrey/RIOT,dhruvvyas90/RIOT,wentaoshang/RIOT,Josar/RIOT,stevenj/RIOT,x3ro/RIOT